Composition, method and apparatus for soil remediation

ABSTRACT

A composition, process and apparatus for soil remediation on site using an encapsulating agent to separate contaminants from soil. The contaminated soil is saturated with the encapsulating agent, creating an immediate reaction causing the contaminants to dissociate from the soil in favor of association with the encapsulating agent. The encapsulating agent attracts and associates with the contaminants but do not dissolve them, resulting in a clearly-defined heterogeneous mixture with at least three phases, wherein said phases include contaminants at the top of the mixture, encapsulation agent at the middle and cleansed soil at the bottom of the mixture. The encapsulating agent comprises an anionic surfactant, an alcohol, a non-ionic surfactant, pine oil and water. The soil remediating apparatus is preferably portable and provide for a closed-loop continuous cleaning of the soil, which is immediately returned to the original site, and recycling the encapsulating agent back into the remediation process.

RELATED APPLICATIONS

The present disclosure is a continuation of application Ser. No.14/196,891, filed on Mar. 4, 2014.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AMD DEVELOPMENT

N/A

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present invention relates to a composition, method and apparatus forremoving soil contaminants, and more particularly for the removal ofsoil contaminants by saturating the contaminated soil with a recyclable,non-toxic encapsulation agent that separates oil and other contaminantsfrom the soil.

Discussion of the Background

Soil contamination has become a major problem because of the largeamounts of man-made pollutants and chemicals that have been put into theenvironment. These contaminants affect the environment and endangerpeople's health. People's health can be damaged by various ways; forexample, by touching the soil, or by breathing the air in the area wherethe soil is. In addition to the foregoing, the people's health may beendangered due to ground water contamination as a direct result of thesoil contaminants. Federal and state laws have been enacted to mandatethe clean-up of both intentional and unintentional contaminated sites.

The most common causes of soil contamination are oil, diesel, gasoline,petroleum-based products or other hydrocarbons exposed over a surface,including soil and sand, or a body of water due to oil spills andothers. Major sources of these contaminants are refineries, gasstations, chemical plants and oil industries.

Currently, several apparatus and methods are used to clean-upcontaminated soil. Alcohol, petroleum-based solvents or water are amongthe methods used to dissolve the contaminants from the soil and thenreturn the cleansed soil to the original site. However, these processeshave a number of disadvantages. For instance, the solvent used in thoseprocesses dissolves the contaminants from the soil resulting in ahomogeneous mixture of solvent/contaminant. In these cases, it requiresdifferent or several post-treatment processes, such as distillation, toseparate the solvent/contaminant mixture in order to re-use the solventin the soil remediation process as well as to properly dispose thecontaminant pursuant to federal and state law. These post-treatmentprocesses are expensive and time consuming.

Furthermore, in most processes large amounts of solvent is needed tocompletely clean the soil thus making the process expensive andineffective. Also some of the solvents used in the art are toxic thusrequiring post-treatment of the soil before returning it to the originalsite.

Therefore, there is a need for a composition, method and apparatus fortreatment contaminated soil on site which uses a non-toxic encapsulatingagent that can effectively separate or remove contaminants from soil butalso that can be amenable to an easy separation from the contaminant. Inlight of this, the contaminants may be disposed pursuant to federal andstate law, and the non-toxic encapsulating agent may be recycled back inthe remediation process.

Thus, in view of the above-mentioned deficiencies in the act, an objectof the present invention is to provide an encapsulating agent to be usedin soil remediation which is non-toxic, non-flammable and non-harmful toflora or fauna and containing no carcinogens.

It is another object of the present disclosure to provide awater-soluble and biodegradable encapsulating agent.

It is another object of this disclosure to provide a continuous,closed-loop system, which recycles the encapsulating agent in the soilremediation process.

It is another object of the present disclosure to provide a method andcomposition simple and cost-efficient for removing soil contaminants.

Further another object of the present disclosure is to provide anapparatus for using a recyclable encapsulating agent that separatesefficiently contaminants from soil at the original contaminated site.

Furthermore, the encapsulation agent of the present disclosure iseffective for acting as a cleaning solvent for petroleum products, suchas oil spill cleanups or removal of tar and grease waste.

SUMMARY

In accordance with the principles of the present invention, a soilremediation composition, method and apparatus are provided. Soilremediation is preferably made at the original contaminated site with aportable remediation apparatus. Contaminated soil is excavated andcleansed in the remediation apparatus with a non-toxic, biodegradableencapsulating agent and then the cleansed soil is returned to theoriginal site free from contaminants. Residues of the encapsulatingagent in the cleansed soil are susceptible to biodegradation and wouldnot harm the environment or the flora at the original site.

The encapsulating agent of the present disclosure comprises an anionicsurfactant, an alcohol, a non-ionic surfactant, pine oil and water. Inaccordance with the principles of the present disclosure, theencapsulating agent is mixed with the contaminated soil with asufficient amount to saturate the contaminated soil. The encapsulatingagent creates an immediate reaction causing the contaminants todissociate from the soil in favor of association with the encapsulatingagent. The admixture of contaminated soil and encapsulating agent isagitated for a period of time sufficient to permit complete contactbetween the encapsulating agent and the contaminated soil to promotefull disassociation of the contaminants from the soil in favor ofassociation with the encapsulating agent. The encapsulating agentattracts and associates with the contaminants but does not dissolvethem, resulting in a clearly-defined heterogeneous mixture with at leastthree phases, wherein said phases include contaminants at the top of themixture, encapsulation agent at the middle of the mixture and cleansedsoil at the bottom of the mixture.

The cleansed soil is free from contaminant or contains residues ofcontaminants at levels permitted by federal and state law and thus canbe returned to the original site. The contaminants such as oil, diesel,gasoline or other hydrocarbons are easily separated from theheterogeneous mixture comprising encapsulating agent/contaminants by askimming process. The encapsulating agent is then recycled back into thesoil remediation process of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which ate incorporated herein, constitutepart of the specification and illustrate the preferred embodiment of thedisclosure.

FIG. 1 shows a general structure of the present disclosure in accordancewith the principles of the present disclosure.

FIG. 2 shows a more detailed embodiment of the method and apparatus forremediation of soil of the present disclosure in accordance with theprinciples of the present invention.

FIG. 3 shows an exemplary embodiment of the method and apparatus forremediation of soil between the shaker and the encapsulating agent tankin accordance with the principles of the present disclosure.

FIG. 4 shows an exemplary embodiment of the method and apparatus for thethird chamber of the encapsulating agent tank in accordance with theprinciples of the present disclosure.

FIG. 5 shows a flow chart of the exemplary process for treatingcontaminated soil in accordance with the principles of the presentdisclosure.

FIG. 6 shows the effectiveness of the encapsulating agent when salinewater (water with salt) is used. Due to the fact that the encapsulatingagent may use sea water as the water component, it lowers the costs inobtaining or using deionized water.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The encapsulating agent of the present disclosure comprises an anionicsurfactant, an alcohol, a non-ionic surfactant, pine oil and water.

Anionic Surfactant

Anionic surfactants suitable to be used in the present inventioninclude: sodium lauryl sulfate, alkali metal salts, ammonium salts,alkyl sulfates, alkyl ether sulfates, and generally the alkyl or acylradical in these various compounds comprise a carbon chain containing 12to 20 carbon atoms. In the preferred embodiment the anionic surfactantis sodium lauryl sulfate, preferably the composition commerciallyavailable under the tradename Lessrex 70®.

The anionic surfactant may be present in the compositions in amounts ofup to about 6% by weight, but most preferably in amount of between from0.8% to 3%.

Alcohol

Exemplary alcohols to be used in the present invention to enhance themiscibility of the pine oil in water include: lower alkyl alcohols,especially C₁-C₈ alcohols, preferably isopropyl alcohol, propanol andethanol. In the preferred embodiment the alcohol is isopropyl alcohol.

The alcohol may be present in the compositions in amounts of up to about6% by weight, but most preferably in amount of between from 0.8% to 3%.

Nonionic Surfactants

Nonionic surfactants suitable for the present invention includecondensation products of one or more alkylene oxide groups with anorganic hydrophobic compound, such as an aliphatic or alkyl aromaticcompound. Suitable nonionic surfactants include alkoxylated alcoholswhich include ethoxylated alcohols.

Exemplary alkoxylated alcohols include certain ethoxylated alcoholcompositions commercially available include Neodol® from Sheel Company,which is described as a linear alcohol ethoxylate, Tergitol® from UnionCarbide Co. (Danbury, Conn.), which is described as a secondary alcoholethoxylate, and Imbirex CR® from American Chemical, which is describedprimary as an alcohol ethoxylated. In the preferred embodiment thenonionic surfactant is an ethoxylated alcohol, preferably thecomposition commercially available under the tradename Imbirex CR®.

The nonionic surfactant may be present in the compositions in amounts ofup to about 3% by weight, but most preferably in amount of between from0.4% to 1.5%.

Pine Oil

Pine oil is a complex blend of oils, alcohols, acids, esters, aldehydes,and other organic compounds. These include terpenes which include alarger number of related alcohols or ketones. Preferred terpenes aremono- and bicyclic monoterpenes, especially those of the hydrocarbonclass, which can be selected from terpinenes, terpinolenes, limonenesand pinenes. Highly preferred materials of this type include d-limonene,dipentene, α-pinene, β-pinene and the mixture of terpene hydrocarbonsobtained from the essence of oranges.

Particularly effective pine oils which are presently commerciallyavailable include Unipine®60 (from Union Camp, which is believed tocontain approximately 60% terpene alcohols), Unipine® S-70 and Unipine®S-70 (from Union Camp, both are believed to contain approximately 70%terpene alcohols), and any other pine oil up to 100% terpene alcohol.Other examples of commercially available pine oils can be found in U.S.Pat. No. 5,728,672.

The pine oil may be present in the compositions in amounts of up toabout 6% by weight, but most preferably in amount of between from 0.8%to 3%.

Water

Deionized water, tap water or sea water may be used in the presentinvention. Surprisingly, using sea water (water with concentration ofsalts of about 1%-5%) provides with a better encapsulating agent forremoving soil contaminants. Because sea water may be used in the presentinvention, it lowers the cost in obtaining or using deionized water.

Water may be present in the compositions in amounts of up to about 97%by weight, but most preferably in amount of between from 90% to 95%.

In one embodiment of this disclosure, the anionic surfactant is mixedwith the alcohol in equal parts and stirred until a homogeneous phase isachieved and it shows luminous halos. The resulted mixture is blendedwith the non-ionic surfactant and stirred until a homogeneous phase isachieved. The resulted mixture is further blended with the pine oil andstirred until a homogeneous phase is achieved. The resulted mixture isfurther blended with water and stirred until a homogeneous phase isachieved. Then, the mixture is allowed to rest. The resulting mixture isthe encapsulating agent 30.

In accordance with the principles of the present invention, a soilremediation process is performed on-site of the contaminated area,allowing in the case of contaminated sand to be cleansed and returned tothe beach restoring the site. Therefore, the apparatus is preferablyportable.

The term soil includes: soil, sand, and other solid surfaces such aspetroleum tanks. Also it includes water, and other liquid surfaces whichhave been contaminated with contaminants. The term contaminants include,but is not limited to, oil gasoline, diesel, petroleum-based productsand other hydrocarbons.

Referring now to the drawings, FIGS. 1-5 shows a soil remediationprocess and apparatus embodying the principles of the present invention,which is designated generally by the reference number 100.

The soil remediation process starts with the collection of thecontaminated soil on site. A loader or bobcat is used to excavate fromthe ground the contaminated soil and is delivered to the portable, soilremediation apparatus 100 via a hopper 5. In one embodiment of thepresent disclosure, the hopper 5 contains at its entrance asize-limiting screen 21. Contaminants may act as binders that canagglutinate the soil with other materials such as stones, rocks, thesame soil, and other materials. In this instance, the particle size ofthe soil will be larger than the median particle size of the soil atthat site. Agglomeration, also, may prevent the encapsulating agent 30to fully remove the contaminants from soil.

In light of the foregoing, it is preferred that a study of thecharacteristics of the soil is performed to determine the medianparticle size of the soil. The size of the limiting screen 21 will beequal or similar to the median particle size. In this case, thesize-limiting screen 21 will prevent the passage of large, agglutinatedparticles to the soil remediation process 100. Instead, thoseagglutinated particles are deposited into a grinder, as shown in FIG. 1,that mechanically breaks the agglutinated soil into a particle sizeequal or similar to the median particle size. The purpose of this is toavoid any damages or changes in the characteristics of the soil in theremediation process, allowing the site to retain its characteristicswhen the soil is returned. Also breaking the agglutinated soil intosmaller particles increases the surface area that will be in contactwith the encapsulating agent 30, thus facilitating the removing ofcontaminants.

The contaminated soil is transported from the hopper 5 by means of aconveyer belt or any other transporting means and deposited into a mixerM.

An encapsulating agent tank 50, as shown in FIG. 2, contains at leastthree chambers: a first chamber 50 a, a second chamber 50 b and a thirdchamber 50 c. The encapsulating agent tank 50 is partially filled withthe encapsulating agent 30 before any contaminated soil is introducedinto the soil remediating apparatus 100.

The encapsulating agent 30 is transferred from the first chamber 50 a ofthe encapsulating agent tank 50 to the mixer M with a pump P10, as shownin FIG. 2. The contaminated soil is stirred, mixed and blended with theencapsulating agent 30 in the mixer M by means of blades, mixers,stirrers, electric motor or any other agitation unit capable of mixingthe contaminated soil with the encapsulating agent 30.

The contaminated soil is saturated with the encapsulating agent 30 inthe mixer M. Preferably the ratio of encapsulating agent 30 tocontaminated soil is at least 3:1. Once the contaminated soil issaturated with the encapsulating agent 30 for a period of timesufficient to allow complete interaction between them, the encapsulatingagent 30 creates an immediate reaction causing the contaminants 31 todissociate from the soil in favor of association with the encapsulatingagent 30.

The admixture 3 comprising contaminated soil and encapsulating agent 30is transported upward from the mixer M to at least one soil shaker 12 bymeans of an impeller pump P1 or any other transporting means, capable ofmoving both the solid (soil) and the liquids (contaminants 31 andencapsulating agent 30), as shown in FIG. 1. At this point, theencapsulating agent 30 has attracted most of the contaminants 31,resulting in a heterogeneous mixture of mainly two phases. The firstphase is substantially a solid phase comprising cleansed soil, whichcontains larger particles, and the second phase is substantially aliquid phase comprising the contaminants 31 and the encapsulating agent30, which contain smaller particles.

As shown in FIG. 3, the shaker 12 comprises a screen 23 having aparticular mesh size. Usually shaker 12 is shaken with reciprocatinglinear movement along a horizontal axis. The movement is designed tocause material resting on the screen 23 to slide forward slightly witheach cycle of motion, and perhaps falling through one of the holes 121if the particle is small enough. Due to the fact that the cleansed soilcontains large particles, said cleansed soil does not fall through thescreen 23, and the cleansed soil is eventually ejected off of theforward end of the screen 23 into a recovery soil tank 15 for immediatereturn to the site.

The cleansed soil may contain traces of contaminants 31 but are atlevels permitted by federal and state environmental regulations.Furthermore, the cleansed soil may contain traces of the encapsulatingagent 30. However, the cleansed soil may be returned to the originalsite safely since the encapsulating agent 30 is non-toxic andbiodegradable.

Soil shaker 12 is preferably positioned directly over the third chamber50 c of the encapsulating agent tank 50, as shown in FIG. 3. The liquidphase passes through the shaker screen 23 and falls into the thirdchamber 12 c. Also small particles of soil 8 pass through the shakerscreen 23 and falls into the third chamber 50 c.

In the third chamber 50 c of the encapsulating agent tank 50, theprocess for the separation of the components of the liquid phase starts.FIG. 3 explains the separation process more in details. Mainly theliquid phase is allowed to rest inside the third chamber 50 c. Due totheir differences in densities each component of the liquid phase startsto separate from each other providing two layers. The contaminants 31,being less dense than the encapsulating agent 30, will tend to float tothe top of the liquid phase. The encapsulating agent 30 will tend torest at the bottom of the liquid phase. The smaller particles of soil 8will tend to settle at the bottom of the third chamber 50 c.

The contaminants 31 at the top of the liquid phase are removed with apump P3 into a contaminant recovery tank 40. The pump P3 is preferablypositioned at a predetermined height H3 of a first wall W1 of the thirdchamber 50 c, as shown in FIG. 4. The height H3 is adjusted inconjunction with the flow rate of the contaminated soil entering theapparatus 100 and the pump P10 to cause a predetermined depth of fluidto be continuously removed from the top of the liquid phase of the thirdchamber 50 c into the recovery contaminant tank 40.

The recovered contaminant 31 in the recovery contaminant tank 40 isessentially free from the encapsulating agent 30 and the smaller soilparticles 8. In the case that the contaminant 31 is oil, the recoveredoil may be used as heating oil or any other oil fuel application.

The third chamber 50 c also contains a second wall W2, which is oppositeto the first wall W1, as shown in FIG. 3. The encapsulating agent 30 inchamber 50 c flows to the second chamber 50 b by means of an inlet INlocated at the bottom of the second wall W2. The inlet IN is positionedat a predetermined depth of the second wall W2 in order to prevent thatany contaminant 31 that is floating at the top of the liquid phase inchamber 50C passes to chamber 50 b. The liquid phase that flows fromchamber 50 c to the second chamber 50 b comprises only the encapsulatingagent 30 and some smaller particles of soil 8, which will tend to settleat the bottom of the second chamber 50 b.

The second chamber 50 b contains a first skimming wall W3, which isopposite to the second wall W2, as shown in FIG. 3. The encapsulatingagent 30 in the chamber 50 b flows over the first skimming wall W3 tothe first chamber 50 a. Most of the smaller soil particles 8 areretained at the bottom of chamber 50 b. Only a minimum amount of smallerparticles of soil 8 passes with the encapsulating agent 30 by overflowto chamber 50 a.

Small particles of soil 8 in chambers 50 a, 50 b and 50 c have aparticle size smeller than 35-40 microns. Particles of this size becomevery difficult to separate with soil shakers. In order to remove thesmaller soil particles 8 from the encapsulating agent 30 in each of thechambers 50 a, 50 b and 50 c, it is preferred to pass the fluidcontaining said small particles of soil 8 through a desilter unit 25,which are known in the industry as “hydrocyclones”, as shown in FIG. 2and FIG. 4.

The desilter unit 25 is preferably positioned directly over the secondchamber 50 b, as shown FIG. 2. The desilter unit 25 separates the smallparticles of soil 8 from the encapsulating agent 30. Each chamber 50 a,50 b, and 50 a contains a pump P30 at its bottom that transfers thefluid containing encapsulating agent 30 and small particles of soil 8 tothe desilter unit 25, as shown in FIG. 3.

The small particles of soil 8 recovered from the desilter unit 25 areforward to the recovery soil tank 15. The encapsulating agent 30, whichis not retained in the desilter unit 25, falls into the second chamber50 b essentially free from smaller soil particles 8.

Through the actions of the separation process through difference indensities of the encapsulating agent 30 and the contaminants 31 inchamber 50 c, in combination to the progressive skimming in theencapsulating agent tank 50, with the soil shaker 18 and the desilterunit 25, the encapsulating agent 30 of the first chamber 50 a issubstantially free from contaminants 31 and smaller soil particles 8and, therefore, is available, to be recycled back to the remediationprocess of the present disclosure.

The recirculation of the encapsulating agent 30 in the closed-loopremediation process, over time, will cause the concentration of theencapsulating agent 30 to decrease. In this case, new amounts ofencapsulating agent 30 must be introduced into the system. Themonitoring of the concentration of the encapsulating agent 30 may bedone by manual sampling, visual inspection or with an optical detectionsystem (not shown) that automatically monitors the light transmissivityof the encapsulating agent 30, as is known.

EXAMPLES

Table 1. shows the results of several tests performed to evaluate theeffectiveness of the encapsulating agent in removing oil and othercontaminants from sand. Different amounts of oil and other contaminantswere added to a sand sample in the several tests. The encapsulatingagent comprises: 1.43% of Lessrex 70® (sodium, lauryl sulfate), 1.43% ofisopropyl alcohol, 0.71% of Imbirex CR®(ethoxylated alcohol), 1.43% ofpine oil and 95% of water. After saturating the contaminated sand withthe encapsulating agent, as can be observed from the results in Table 1,in all trials the TPH in the samples were low with over 90% of oilrecovery.

Concentration 5% Active Ingredient of Encapsulating Agent Initial TPH orpercentage Oil Percentage Total Recovered Percentage of oil in Volume ofOil and Petroleum Volume of samples (ML) grease Hydrcarbon (MI) Recovery 5% 6.5 .30% 0.14 6.1 93.84% 10% 12.5 .34% 0.16 12.1 96.80% 15% 19.5.68% 0.32 18.6 95.38% 20% 27.5 .72% 0.36 26.5 96.36%

What is claimed is:
 1. An encapsulating agent for soil remediationcomprising: i) an anionic surfactant, ii) an alcohol; iii) a non-ionicsurfactant; iv) pine oil; and v) water.
 2. An encapsulating agent as inclaim 1 comprising: i) 0.8-6% wt. of an anionic surfactant, ii) 0.8-6%wt. of an alcohol; iii) 0.4-3% wt. of a non-ionic surfactant; iv) 0.8-6%wt. of pine oil; and v) 90-97% wt. of water.
 3. An encapsulating agentas in claim 1 comprising: i) 0.8-6% wt. of sodium lauryl sulfate; ii)0.8-6% wt. of isopropyl alcohol; iii) 0.4-3% wt. of ethoxylated alcohol;iv) 0.8-6% wt. of pine oil; and v) 90-97% wt. of water.
 4. An apparatusfor soil remediation comprising: a mixer; a transportation unit, aplurality of pumps comprising at least a first pump and a second pump;at least a shaker; at least a hydrocyclone; an encapsulating agent; anencapsulating agent tank filled with said encapsulating agent; whereinthe encapsulating agent is mixed with a contaminated soil in the mixerto form an admixture, said contaminated soil having contaminants,wherein said transportation unit provides a path between the mixer andat least said shaker; wherein said admixture comprises at least a firstphase and a second phase; wherein said shaker is positioned on top ofsaid encapsulating agent tank; wherein said shaker separates the firstphase from the second phase; wherein the second phase is deposited inthe encapsulating agent tank; wherein the second phase comprises a firstdensity and a second density; wherein said first pump is configured toremove the first density of the second phase from said encapsulatingagent tank; wherein said second pump is configured is configured totransport the second density of the second phase toward the mixer. 5.The apparatus for soil remediation as in claim 16, further comprising atleast an hydrocyclone for removing a sediment from the second density ofthe second phase.
 6. The apparatus for soil remediation as in claim 16,wherein said encapsulating agent is water-soluble and biodegradable. 7.The apparatus for soil remediation as in claim 16, wherein saidencapsulating agents comprising: i) an anionic surfactant, ii) analcohol; iii) a non-ionic surfactant; iv) pine oil; and v) water.
 6. Theapparatus for soil remediation as in claim 16, wherein saidencapsulating agents comprising: i) 0.8-6% wt. of sodium lauryl sulfate;ii) 0.8-6% wt. of isopropyl alcohol; iii) 0.4-3% wt. of ethoxylatedalcohol; iv) 0.8-6% wt. of pine oil; and v) 90-97% wt. of water.